Remote starting system for diesel engines

ABSTRACT

A system is disclosed for starting a diesel engine from a remote location utilizing a receiver for receiving a command signal from a remote location and generating an engine start signal in response thereto. The start signal actuates an energizing circuit which connects a potential source to a fuel feed mechanism, and which, in response to control signals from a two-stage time delay start mechanism, connects the potential source to the starter motor for the engine. A protection mechanism is coupled to the engerizing circuit and automatically de-energizes such circuit and positively terminates the feeding of fuel to the engine, thereby stopping the engine, upon the occurrence of any one of a number of predetermined events, including &#39;&#39;&#39;&#39;racing&#39;&#39;&#39;&#39; of the engine; &#39;&#39;&#39;&#39;grinding&#39;&#39;&#39;&#39; of the engine without starting; or &#39;&#39;&#39;&#39;idling&#39;&#39;&#39;&#39; of the engine for a predetermined period of time.

Bucher I .1 1 Jan. 21, 1975 1 REMOTE STARTING SYSTEM FOR DIESEL ENGINES [76] Inventor: Jeffry C. Bucher, R.D. No. 1,

v Aspers, Pa. 17304 22 Filed: Feb. 14, 1973- [21] Appl. No.: 332,246

[52] US. Cl. 290/37, 290/38, 123/179 B [51] Int. Cl. F02n 11/08, F02n 11/10 [58] Field of Search 123/179 R, 179 B; 290/37, 290/38 [56] References Cited UNITED STATES PATENTS 2,741,086 4/1956 Machlanski 290/38 R X 2,857,900 10/1958 Neely 123/187.5 R 3,478,730 1 H1969 Bucher 290/38 R X 3,514,621 5/1970 Farmer et a1. 123/179 A 3,530,846 9/1970 Bean et al 290/38 3,562,542 2/1971 Redmond 290/37 X 3,577,164 5/1971 ReBaratelli et a1. 290/37 R X 3,657,720 4/1972 Avdenko et a1. 290/37 A 3,685,606 8/1970 290/38 3,793,529 2/1974 Bucher 290/37 X FOREIGN PATENTS OR APPLICATIONS I 668,169 8/1963 Canada 123/179 B Primary Examiner-Charles J. Myhre Assistant ExaminerW. Rutledge, .lr.

Attorney, Agent, or FirmSchuyler, Birch, Swindler, MeKie & Beckett [57] ABSTRACT in response to control signals from a two-stage time delay start mechanism, connects the potential source to the starter motor for the engine. A protection mechanism is coupled to the engerizingcircuit and au-- tomatically de-energizes such circuit and positively terminates the feeding of fuel to the engine, thereby stopping the engine, upon the occurrence of any one I of a number of predetermined events, including racing of the engine; grinding" of the engine without starting; or idling of the engine for a predetermined period of time.

11 Claims, 3 Drawing Figures v ETHER so| R41 0R GLOW PLUGS D35 ACCESSORIES K2 K38 o T STARTER I 031 SOL. 03a Kl FUEL 5cm SOL.1 039 014 FUEL 0 soez '1 GO J Pmmgnmzl ms SHEEI 2 OF 3 Nmm REMOTE STARTING SYSTEM FOR DIESEL ENGINES BACKGROUND OF THE INVENTION The present invention is an improvement of the remote starting system disclosed in Pat. No. 3,478,730. The system disclosed in said patent was a substantial improvement over the known devices for starting combustion engines from a remote location, and the system disclosed herein incorporates certain desirable additional features and improvements, and in particular additional features and improvements adapted for starting a diesel engine from a remote location. The aforesaid patent sets forth the background of the invention in detail, including citations of prior art of interest.

Subsequently issued Pat. No. 3,685,606 also is ofinterest, but does not disclose or suggest the novel features and attendant advantages of the system disclosed herein.

SUMMARY OF THE INVENTION The system of the invention is designed to start, from a remote location, a diesel engine having an electric starter motor, an electric generating device and a source of electric potential associated therewith. The starting system utilizes a' receiver for receiving a coded command signal from a remote location and generating an engine start signal in response thereto, and an energizing circuit for connecting the potential source to a fuel feed mechanism and, in response to control signals from a two-stage time delay start mechanism, to the starter motor. A protection mechanism also is coupled to the energizing circuit for de-energizing such circuit and positively terminating the feed of fuel to the engine, thereby stopping the engine, upon the occurrence of any one of a number of events, including an indication that the engine is racing; an indication that the tion is described in detail in connection with the following drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1A, 1B and 1C are schematic diagram of the remote starting system of the invention, with otherwise unidentified circuit lines which bridge the drawings identified by lower case letters.

DESCRIPTION OF THE PREFERRED EMBODIMENT In the preferred embodiment of the system of the invention, a radio receiver is mounted adjacent a diesel engine for receiving a coded command signal from a radio transmitter carried by an operator. The receiver and transmitter may be of the type described in the aforementioned Pat. No. 3,478,730. The system includesmeans triggered by the receiver in response to receipt of the command signal for energizing a fuel feed mechanism and a starter motor associated with the engine. Specifically, an engine start signal from the receiver is applied to an energizing switching circuit which connects a source of electric potential to a fuel feed mechanism and the starter motor.

The main power supply line for the system, designated BAT, is connected to a potential source, such as a conventional storage battery. The energizingcircuit includes single pole, single throw relays K1, K2 and K5,

double pole, single throw relay K3, single pole, double throw relay K4, and timing devices U1 and U4. An engine start signal from the receiver of less than five seconds duration in the form of grounding the terminal designated RECEIVER OUTPUT is coupled through a resistor R13 to the base ofa PNP transistor 05, turning on such transistor. The emitter of transistor of O5 is connected to the BAT line on the positive side of switch K1, and the collector thereof is connected through a diode D12 to one end of the coil of relay K1 and additionally through three resistors R24, R25 and R2 to the system ground, designated G. The base of an NPN transistor Q12 is connectto the junction between resistors R24 and R3. The same end of the coil of relay K1 is that is connected to the collector of transistor 25 also is connected to the BAT line on the negative side of switch Kl. The collector-emitter circuit of transistor Q12 is connected between the other end of the coil of relay K1 and ground. Thus, when transistor 05 is turned on, transistor 012 also is turned on, connecting the other end of the coil of relay Kl to ground, as result of which the relay is energized. The normally open switch of relay K1, which is inserted in the BAT line, is then closed. The base of transistor O12 is then coupled directly to the BAT line, and the coil of relay K1 is coupled directly between the BAT line and ground through the collector-emitter circuit of transistor OI2. Thus, when relay K1 is energized, the switch of the relay is locked closed.

The engine start signal also results in the momentary .grounding of one end of the coil of relay K3, the other end of which is connected to the BAT line on the positive side of switch K1, resulting in the momentary energization of such relay. When relay K3'is energized, normally open switches K3A and K3B thereof are closed.

The movable contact of switch K3A is connected to the I normally closed stationary contact of switch K4. The movable contact of switch K4 is connected to the BAT line. The stationary contact of switch K3A is connected to a fuel feed device, designated FUEL SOL 1, comprising a solenoid connected to the throttle valve of the engine for opening such valve. Thus, when relay K3 is energized, potential is applied to deviceFUEL SOL 1 via switches K4 and K3A,- thereby feeding fuel to the I engine prior to the starting thereof. As soon as the receiver output terminals, relay K3 is de-energized, thereby opening switch K3A and de-energizing device FUEL SOL l. 1

The main bias supply voltage for timing devices U1 and U4 as well as additional timing devices U2, U5, U6 and U3 is supplied by a voltage divider comprising a diode D3, two resistors R16 and R17 connected in series and a capacitor .C1 connected in parallel with the two resistors. This arrangement, whereby the bias supply voltage is tapped off at the junction between resistors R16 and R17, supplies a standardized voltage level to all of the above-identified timing devices. This is necessary because frequently one or more accessories are associated with the engine which are energized by the battery during the operation of the starting system. The voltage divider stabilizes the bias voltage to the timing devices, thereby avoiding degradation in the timing functions which might otherwise result.

When relay K1 is energized, the proper bias voltage is applied to the biasing input of each of timing devices 3 U1-U6 from bias line 60 by means of biasing resistors R6, R28, R9, R31, R35 and R12, respectively. [n the preferred embodiment, each timing device is a threshold voltage device, which turns on only when an inpupt signal of a certain magnitude exceeding a predetermined threshold level is applied to a control input thereof. Each timing device turns off when the control input thereof is grounded. In the preferred embodiment, each timing device comprises a silicon controlled switch. A series RC network is coupled to the control input of each timing device to establish the time lag before the threshold level voltage needed to turn on the device is achieved.

Timing device U1 comprises the first stage of a twostage time delay start mechanism for starting the engine, which stage is specifically intended either to energize a device for feeding ether to'the engine or to apply potential to the glow plugs of the engine, if the engine includes such plugs, before energizing the starter mo.- tor. Device U1 has the control input 62 thereof connected to the junction between two resistors R and R18 which are connected in series with a capacitor C2 between the BAT line and ground.

A voltage signal begins to develop at control input 62 as soon as relay K1 is energized. In the preferred embodiment, a voltage signal of sufficient magnitude to turn on device U1 develops at control input 62 about five seconds after relay K1 is energized. This time delay period, as well as the delay periods of the other timing devicesv U2-U6, has been selected to meet the exigencies of the preferred embodiment disclosed herein which is adapted for use with a standard diesel engine of present commercial design.

When the signal applied to control input 62 of device U1 reaches the threshold level and the device is turned on, a signal is generated at the output thereof and is applied to the base of an NPN transistor Q6, turning on such transistorQThe collector-emitter circuit of transistor O6 is coupled between the base of a PNP transistor Q2 and ground. Thus, when transistor Q6 is'turned on, transistor Q2 also is turned on. The emitter of transistor O2 is connected to the BAT line, and the collector thereof is coupled to one end ofthe coil of relay K5; the

other end of such coil being connected to ground. Thus, when transistor 02 is turned on, relay K5 is energized closing the normally open switch thereof. The movable contact of switch K5 is connected to the BAT line and the stationary contact is connected to the device for feeding ether to the engine, designated ETHER SOL, or to the glow plugs, designated GLOW PLUGS. Device ETHER SOL may comprise a solenoid operatively connected to a valve for feeding ether to the engine. Thus, when relay K5 is energized, either device ETHER SOL is energized or potential is applied to the GLOW PLUGS.

The collector of transistor Q2 also is coupled to the gate of a silicon controlled rectifier SCRl. The anodecathode circuit of rectifier SCRl is connected in series with the coil of relay K4 between the BAT line and ground. Thus, when transistor O2 is turned on, rectifier SCRl also is turned on and relay K4 is energized moving the movable contact of the switch thereof into contact with the normally open stationary contact thereof. The latter contact is connected to the movable contacts of switches K2 and K38 and to any accessories associated with the engine. Thus, when relay K4 is energized potential is removed from switch K3A so that .4 device FUEL SOL l willlnot be energized even if relay K3 is again energized.

Timing device U4 comprises the second stage of the start mechanism, which stage is specifically intended to energize the starter motor, designated STARTER SOL,

a short time after ether has been fed to the engine or potential has been applied to the glow plugs. Device U4 has the control input 64 thereof connected to the junction between a variable resistor R27 and a fixed resistor R41 which are connected in series with a capacitor C6 between the collector of transistor Q2 and ground.

A voltage signal begins to develop at control input 64 as soon as transistor O2 is turned on. In the preferred embodiment, a voltage signal of sufficient magnitude to fire device U4 develops at control input 64 about one second after transistor 02 is turned on. The delay period of device U4 may be varied by adjusting resistor R27 and is dependent upon whether the engine includes the device ETHER SOL or GLOW PLUGS.

When the signal applied to control input 64 of device U4 reaches the threshold level and the device is turned on, a signal is generated at the output thereof and is applied to the base of an NPN transistor Q13, turning on such transistor. The collector-emitter circuit of transistor Q13 is coupled between the base of a PNP transistor Q8 and ground. Thus, when transistor Q13 turned on, transistor Q8 also is turned on. The emitter of transistor O8 is connected to the collector of transistor 02,

and the collector thereof is coupled to one end of the coil of relay K2; the other end of such coil being connected to ground. Thus, when transistor 08 is turned on, relay K2 is energized closing the normally open switch thereof. The stationary contact of switch K2 is connected to the starter motor STARTER SOL. Thus, when relay K2 is energized, after relay K4 hasbeen c nergized, potential is applied to the motor STARTER SOL to thereby start the engine.

An additional feature in this portion of the system is the incorporation of feedback lines in each stage of the two-stage start mechanism to guard against premature cut-off by either of the stages of the respective designated functions. Thus, in the first stage, the collector of transistor O2 is connected to control input 62.of timing device Ul through a diode D4 and a resistor R4 to lock device U1 (and relay K5) turned on until such device is positively turned off. Similarly, in the second stage, the collector of transistor O8 is connected to control input 64 of timing device U4 through a diode D15 and a resistor R26 to lock device U4 (and relay K2) turned on until such device is positively turned off.

The two-stage start mechanism is de-energized in the following manner. When the starting function is complete, and the engine has been running for a sufficient length of time for the electric generating device associated therewith, designated ALT, to generate an output voltage which exceeds the voltage level established by a fixed threshold device comprising a zener diode D9, the diode breaks down and conducts. This voltage level is applied to the base of an NPN transistor Q9 through a resistor R36; the bias level of transistor 09 being established in the quiescent state by a bias resistor R37. Thus, when diode D9 conducts, transistor O9 is turned on. The collector-emitter circuit of transistor 09 is connected between control input 62 of timing device U1 and ground. Thus, when transistor O9 is turned on, control input 62 is shorted to ground and transistors Q6 and Q2 are sequentially turned off, thereby deenergizing relay K5 and removing potential from the device ETHER $01. or GLOW PLUGS and the gate of rectifier SCR 1. However, since rectifier SCRl already is biased into conduction, the rectifier will continue to conduct and relay K4 will remain energized.

When transistor O2 is turned off, control input 64 of timing device U4 also returns to substantially ground potential and transistors Q13 and OS are sequentially turned off, thereby de-energizing relay K2 and the starter motor STARTER SOL.

Should the engine start momentarily and then stop, i.e. stall, timing devices U1 and U4 will again be sequentially turned on to thereby re-start the engine. The reason for establishing a six second delay, i.e. the preferred' combined delay periods of devices U1 and U4, between the energization of relay K1 and the energization of relay K2 is to allow sufficient time for the engine flywheel to stop turning, should the engine start momentarily and then stop, before the starter motor STARTER SOL is again energized.

A protection mechanism, including timing devices U2, U5, U6 and U3 and an additional timing device U7,

detects malfunctions and other predetermined events and in response to such events de-energizes the ener- -gizing circuit and stops the engine. The protection mechanism also may include a two-stage auxiliary equipment control mechanism which sequentially energizes and de-energizes desired auxiliary equipment a' predetermined period of time after the engine has started. The malfunctions detected by the protection mechanism include prolonged energization of the twostage start mechanism indicating that the engine is cuit has been energized. Timing device U2 has the control input 70 thereof connected to the junction between two resistors R8 and R19 which are connected in series with a capacitor C3 between the BAT line and ground.

A voltage signal begins to develop at control input 70 as soon as relay K1 is energized. A voltage signal of sufficient magnitude to turn on device U2 develops at control input 70 the desired predetermined period of time after relay K1 is energized, for example 4 minutes.

When the signal applied to control input 70 of device U2 reaches the threshold level and the device is turned on, a signal is generated at the output thereof and is applied to the base of an NPN transistor Q7, turning on such transistor. The collector-emitter circuit of transistor O7 is coupled between the base of a PNP transistor Q3 and ground. Thus, when transistor O7 is turned on, transistor 03 also is turned on. The emitter of transistor 03 is connected to the BAT line, and the collector thereof is coupled to one end of the coil of a single pole, single throw relay K6; the other end of such coil being connected to ground. Thus, when transistor O3 is turned on, relay K6 is energized closing the normally open switch thereof, thereby energizing the desired auxiliary equipment, designated AUX EQUIP.

The second stage of the auxiliary equipment control mechanism includes timing device US, which stage is intended to de-energize the desired auxiliary equipment a predetermined period of time after such equipment has been energized. Device US has the control input 72 thereof connected to the junction between two resistors R and R42 which are connected in series with a capacitor C7 between the collector of transistor Q3 and ground.

A voltage signal begins to develop at control input 72 as soon as transistor 03 is turned on. A voltage signal of sufficient magnitude to turn on device U5 develops at control input 72 the desired predetermined period of time after relay K6 has been energized, for example 2 minutes. I 7

When the signal applied to control input 72 of device U5 reachesthe threshold level and the device is turned on, a signal is generated'at the output thereof and is applied to the base of an NPN transistor Q14, turning on such transistor. The collector-emitter circuit OfifllflSlS- tor 014 is connected between control input 70 of device U2 and ground. Thus, when transistor O14 is turned on, control input 70 is shorted to ground and transistors O7 and Q3 are sequentially turned off, thereby de-energizing relay K6 and the previously energized auxiliary equipment.

The collector-emitter circuit of transistor Q14 also is coupled to the base of a PNP transistor Q4. Thus, when transistor Q14 is turned on, transistor Q4 also is'turned on. The emitter of transistor O4 is connected to the BAT line, and the collector thereof is coupled to con- 7 trol input 72 of device U5, thus locking transistors Q14 and Q4 turned on after transistors Q7 and-Q3 .are turned off. This is necessary because of the functional interrelationship between timing devices U5 and U3, as

described below.

Timing devices U3 and U7 comprise an engine stop mechanism which stops the engine a predetermined period of time after remote starting thereof. Device U3 has the control input thereof connected between two resistors R11 and R20 which are connected in series with a capacitor C4 between the collector of transistor Q4 and ground.

A voltage signal begins to develop at control input 80 assoon as transistor O4 is turned on. In the preferred embodiment, avoltage signal of sufficient magnitude to turn on device U3 develops at control input 80 about twelve minutes after relay K1 is energized, for example about six minutes after transistor O4 is turned on. As is apparent, the sum of the delay periods of devices U2, U5 and U3 which are turned on sequentially determine the total delay period between the energization of relay K1 and the turning on of device U3.

When the signal applied to control input 80 of device U3 reaches the threshold level and the device is turned on,'a signal is generated at the output-thereof and is applied to the base of an NPN.transistor Q15, turning on such transistor. The collector-emitter circuit of transistor Q15 is connected between the junction between resistors R25 and R24 and ground. Thus, when transistor Q15 is turned on, the base of transistor Q12 and the end of the coil of relay Kl connected to the BAT line are shorted to ground, thereby de-energizing relay K1 and turning off transistor Q12. When relay K1 is deenergized potential is removed from timing devices U1-U6 and the energizing circuit is de-energized.

Since a diesel engine generally has no ignition system and therefore cannot be stopped by de-energizing such a system, the protection mechanism also includes means for positively terminating the feeding of fuel to the engine to thereby stop the engine. Such means include timing device U7 a PNP transistor Q17 and an NPN transistor Q18.

The base of transistor Q18 and the control input 82 of device U7 are connected to the collector of transis tor Q12 through diodes D34 and D33, respectively. Thus, as long as transistor O12 is turned on, the base of transistor Q18 and control input 82 are grounded, and transistor Q18 and device U7 remain turned off.

The base of transistor Q18 also is connected to the BAT line on the positive side of switch Kl through a resistor R53. Control input 82 is connected to the junction between two resistors R50 and R52 which are connected in series with a capacitor C9 between the BAT line on the positive side of switch K1 and ground. The biasing input of device U7 also is connected to the BAT line on the positive side of switch K1 through a biasing resistor R51. Thus, when transistor Q12 is turned off, transistor Q18 is turned on and a voltage signal begins to develop at control input 82.

The collector of transistor Q18 is connected to the BAT line on the positive side of switch Kl through two resistors R46 and R47, and the emitter thereof is connected to ground. The base of transistor 217 is connected to the junction between resistors R46 and R47. Thus, when transistor O18 is turned on, transistor O17 also is turned on.

The emitter-collector circuit of transistor Q17 is connected between the BAT line on the positive side of switch K1 and one end of the coil of relay K4, the other end of such coil being connected to the collector of transistor Q18 through a diode D31. Thus, when transistor 012 is turned off and transistors Q18 and Q17 a is energized.

When relay K3 is energized, the normally open switch K3B thereof is closed and potential is applied to a fuel shut off device, designated FUEL SOL 2, comprising a solenoid connected to the throttle valve for closing such valve. When device FUEL SOL 2 is energized, the feeding of fuel to the engine is positively terminated, thereby stopping the engine.

The foregoing sequence for energizing device FUEL SOL 2 occurs substantially instantaneously upon the turning off of transistor Q12, and relays K3 and K4 will remain energized until transistors Q18 and Q17 are turned off. The function of timing device U7 is to turn off such transistors.

In the preferred embodiment, a voltage signal of sufficient magnitude to turn on device U7 develops at control input 82 about 2 seconds after transistor Q12 is turned off.

When the signal applied to control input 82 of device U7 reaches the threshold level and the device is turned on, a signal is generated at the output thereof and is applied to the gate of a silicon controlled rectifier SCR2, turning on such rectifier. The anode-cathode circuit of rectifier SCR2 is coupled between the BAT line on the positive side of switch K1 and ground, The anode of rectifier SCR2 also is connected to the base of transistor 018. Thus, when rectifier SCR2 is turned on, the base of transistor Q18-is grounded, turning off such transistor. When transistor Q18 is turned off, transistor Q17 also is turned off and relays K3 and K4 are deenergized. The energizing circuit is thus de-cnergized and the engine stopped.

The anode'of rectifier SCR2 also is connected to the collector of transistor Q12 through diode D34. Thus, when transistor Q12 is turned on during the starting sequence,. the anode of rectifier SCR2 is grounded, turning off such rectifier and enabling transistor Q18 to perform the function thereof, as described above.

The protection mechanism also includes a malfunction detection mechanism comprising timing device U6 which de-energizes the energizing circuit and stops the engine upon the occurrence of any one of a number of malfunctions. Device U6 has the control input 78 thereof connected to three separate sources for generating a voltage signal. The circuit from each such source includes a resistor R43 and a capacitor C8 connected in series between control input 78 and ground.

A first voltage signal source for device U6 is the normally open stationary contact of switch K2 which is 8 predetermined period of time without the engine starting.

'A voltage signal begins to develop at control input .78 as soon as relay K2 is energized. In the preferred embodiment, a voltage signal of sufficient magnitude to turn on device U6 develops at control input 78 about twelve seconds after relay K2 is energized. Thus, if relay K2 remains energized for about twelve seconds during the starting sequence, indicating that the starter motor STARTER SOL has been energized without the engine starting, the signal applied to control input 78 of device U6 reaches the threshold level and the device is turned on. When device U6 is turned on, a signal is generated at the output thereof and is applied to the base of transistor O15, turning on such transistor and thereby de-energizing the energizing circuit, as described above.

A second voltage signal source for device U6 is the collector of transistor Q3 which is connected to control input 78 through a diode D19 and a resistor R33. The purpose of utilizing the collector of transistor O3 as a voltage signal source is to de-energize the energizing circuit and stop the engine if the auxiliary equipment control mechanism fails to deenergize relay K6 properly.

A voltage signal begins to develop at control input 78 as soon as transistor O3 is turned on. A voltage signal of sufficient magnitude to turn on device U6 develops at control input 78 a predetermined period of time after transistor O3 is turned on, for example, 3 minutes. Thus, if transistor Q3 remains turned on for longer than the desired period of energization for the auxiliary equipment, the signal applied to control input 78 of device U6 reaches the threshold level and the device is turned on, thereby de-energizing the energizing circuit and stopping the engine, as described above.

A third voltage signal source for device U6 is the junction between two isolating diodes D38 and D39 which are connected between the normally open stationary contacts of switches K2 and K3A. The junction between diodes D38 and D39 is connected to control input 78 through the emittercollector circuit of a PNP transistor Q16 and a resistor R45. The purpose of utilizing the junction between diodes D38 and D39 as a voltage signal source is to provide a means for deenergizing the energizing circuit and stopping the engine should either the fuel feed device FUEL SOL l or the starter motor STARTER SOL be improperly energized for any reason whilethe engine is running.

As described above, after the engine has started, transistor O9 is turned on. The base of transistor O16 is coupled to the collector of transistor Q9. Thus, when transistor O9 is turned on, transistor 016 also is turned on. Thereafter, a voltage signal begins to develop at control input 78 if either device FUEL SOL 1 or starter motor STARTER SOL is energized. In the preferred embodiment, a voltage signal of sufficient magnitude to turn on device U6 develops at control input 78 about 2 seconds after either device FUEL SOL l or motor STARTER SOL is energized. Thus, if either the device FUEL SOLl or motor STARTER SOL remains .energized for about 2 seconds after the engine has started,

, throughthe stater motor STARTER SOL when. relay K2 is de-energized. Thus, the charge which builds up on a capacitor C8 during the starting sequence is discharged to ground after the engine starts.

The protection mechanism also includes a two-stage switching'gate for'stopping the engine upon the occurrence of any one of a number of other predetermined events. Such gate includes two NPN transistors Q10 and Q11 having the collector-emitter circuits thereof connected in series between the base of transistor Q12 and ground. The base of transistor Q11 is connected to the electric generating device ALT through zener.

diode D9, a diode D21 and a resistor R22 so that after the engine has started, transistor Q11 is turned on. Thereafter, if transistor Q10 is turned on, the base of transistor Q12 and the end of the coil of relay K1 connected to the BAT line are shorted to ground, thereby de-energizing the energizing circuit and stopping the engine.

One manner of turning on transistor Q10 is by applying an engine start signal from the receiver to the starting system while the engine is running. Thus, should the operator desire to stop the engine from a remote location after remote starting thereof, he generates another command signal from the transmitter, again turning on transistor Q5. The collector of transistor O is connected to the base of transistor Q through a resistor R23 N and a diode D22. Thus, when transistor O5 is turned on, transistor Q10 also is turned on, thereby deenergizing the energizing circuit and stopping the engine, as described above.

When the starting system initially is energized, transistors Q10 and 011 have no effect on relay K1 because transistor Oll is not turned on until the engine has started. Also, the engine stat signal from the receiver is of less than 5 seconds duration so that during the starting sequence, transistor Q10 is turned off before transistor Q11 is turned on. Also, when the energizing circuit is energized, relay K4 is energized as described above, so that when the receiver output is connected to relay K3 while the engine is running, the resulting energization of relay K3 has no effect on the fuel feed device FUEL SOL 1, but will energize fuel shut off device FUEL SOL 2. Thus, when the engine is stopped from a remote location, relay K3 will be energized initially by the receiver output and will be maintained energized by transistor O18, as described above. Another manner of turning on transistor O10 if the engine is mounted in a vehicle is by opening a door of the vehicle. The means for achieving this function include a PNP transistor 01 having the base thereof coupled to the BAT line. The emitter-collector circuit of transistor O1 is connected between the BAT line and the base of transistor Q10 through a diode D], a resistor R15 and a diode D11. ln vehicles having a negative ground lighting system, the door switch is connected to the base of transistor Q1 through a diode D6 and a resistor R3. Thus, when a door is opened, transistor 01 is turned on and transistor O10 also is turned on,

thereby de-energizing the energizing circuit and stopping the engine, as described above.

In vehicles having a positive ground lighting system, the door switch is connected to the base of transistor O10 through a diode D2, resistor R15 and diode D11 so that when a door is opened transistor O10 is turned on, and the energizing circuit is de-energized and the engine stopped, as described above.

An additional manner of turning on transistor O10 if the engine is mounted in a vehicle is by actuating the brakes are actuated transistor 010 is turned on and the energizing circuit is de-energized and the engine stopped, as described above.

If desired, transistor O10 may be turned on by the actuationof an auxiliary-switching device, designated AUX, such as a thermostat. The switching device is r connected to the base of transistor Q1 through a resis- Q10 and de-energizing the energizing circuit and stopping the engine, as described above.

All of the above-described means for turning on transistor 010, except by turning on transistor O5, also will turn on transistor 011 if the engine is not running. The means for achieving this function is a diode D10 connected between the junction between resistor R15 and diode D1 1 and the base of transistor Q11. Thus, the engine need not be running for such means to de-energize the energizing circuit.

While the foregoing constitutes a detailed description of a preferred embodiment of the system of the invention, it is recognized that modifications thereof will occur to those skilled in the art. Therefore, the scope of the invention is to be limited solely by the scope of the appended claims.

I claim:

1. A system for starting, from a remote location, a diesel engine having an electric starter motor, an electric generating device and a source of electric potential associated therewith, said system comprising:

an energizing circuit coupled to a receiver for receiving an engine start signal therefrom and including ll means for connecting saidpotential source to said starter motor in response to said start signal to thereby energize the starter motor, said energizing circuit also being coupled to said generating device for receiving an electric signal therefrom and including means for disconnecting said potential source from said starter motor in response to said electric signal to thereby de-energize the starter motor;

a device for terminating the feeding of fuel to said enginefand a protection mechanism coupled to said energizing circuit and said fuel feed terminating device including means for deenergizing said energizing circuit and energizing said fuel feed terminating device if said starter motor is energized improperly after the engine has started, to thereby stop the engine and prevent damage thereto.

2. A system as recited in claim 1, wherein said engine has a throttle valve for supplying fuel; and wherein said fuel feed terminating device comprises a solenoid for closing said valve.

3. A system as recitedin claim 1; further comprising a device for feeding fuel to said engine; and wherein said energizing circuit includes means for energizing said fuel feed device prior to energizing said starter motor.

4. A system as recited in claim 3, wherein said protection mechanism includes means for de-energizing said energizing circuit and energizing said fuel feed terminating device if said fuel feed device is energized improperly after the engine has started, to thereby stop the engine and prevent damage thereto.

- 5. A system as recited in claim 1, wherein said protection mechanism includesmeans for de-ener'gizing said energizing circuit if the engine does not start within a predetermined period of time after the starter 12 motor is energized by said energizing circuit.

6. A system as recited in claim l wherein said engine has glow plugs; and wherein said energizing circuit includes means for connecting said potential source to said glow plugs prior to energizing said starter motor.

7. A system as recited in claim 1; further comprising means for feeding ether to said engine; and wherein said energizing circuit includes means for energizing said ether feeding means prior to energizing said starter motor.

8. A system as recited in claim 1, wherein said energizing circuit includes at least one time delay means coupled to said means for connecting the potential source to the starter motor to prevent the potential source from being connected to the starter motor for a predetermined period of time after the energizing circuit receives said engine start signal.

9. A system as recited in claim 1, wherein said protection mechanism includes means for de-energizing said energizing circuit and energizing said fuel feed terminating device a predetermined period of time after the engine has been started, to thereby prevent the engine from running unattended for a prolonged periodof time.

10. A system as recited in claim 1, wherein said protection mechanism includes means for de-energizing said energizing circuit-and energizing said fuel feed tera predetermined period of time after said start signal is received by said energizing circuit. l l l 

1. A system for starting, from a remote location, a diesel engine having an electric starter motor, an electric generating device and a source of electric potential associated therewith, said system comprising: an energizing circuit coupled to a receiver for receiving an engine start signal therefrom and including means for connecting said potential source to said starter motor in response to said start signal to thereby energize the starter motor, said energizing circuit also being coupled to said generating device for receiving an electric signal therefrom and including means for disconnecting said potential source from said starter motor in response to said electric signal to thereby de-energize the starter motor; a device for terminating the feeding of fuel to said engine; and a protection mechanism coupled to said energizing circuit and said fuel feed terminating device including means for deenergizing said energizing circuit and energizing said fuel feed terminating device if said starter motor is energized improperly after the engine has started, to thereby stop the engine and prevent damage thereto.
 2. A system as recited in claim 1, wherein said engine has a throttle valve for supplying fuel; and wherein said fuel feed terminating device comprises a solenoid for closing said valve.
 3. A system as recited in claim 1; further comprising a device for feeding fuel to said engine; and wherein said energizing circuit includes means for energizing said fuel feed device prior to energizing said starter motor.
 4. A system as recited in claim 3, wherein said protection mechanism includes means for de-energizing said energizing circuit and energizing said fuel feed terminating device if said fuel feed device is energized improperly after the engine has started, to thereby stop the engine and prevent damage thereto.
 5. A system as recited in claim 1, wherein said protection mechanism includes means for de-energizing said energizing circuit if the engine does not start within a predetermined period of time after the starter motor is energized by said energizing circuit.
 6. A system as recited in claim 1; wherein said engine has glow plugs; and wherein said energizing circuit includes means for connecting said potential source to said glow plugs prior to energizing said starter motor.
 7. A system as recited in claim 1; further comprising means for feeding ether to said engine; and wherein said energizing circuit includes means for energizing said ether feeding means prior to energizing said starter motor.
 8. A system as recited in claim 1, wherein said energizing circuit includes at least one time delay means coupled to said means for connecting the potential source to the starter motor to prevent the potential source from being connected to the starter motor for a predetermined period of time after the energizing circuit receives said engine start signal.
 9. A system as recited in claim 1, wherein said protection mechanism includes means for de-energizing said energizing circuit and energizing said fuel feed terminating device a predetermined period of time after the engine has been started, to thereby prevent the engine from running unattended for a prolonged period of time.
 10. A system As recited in claim 1, wherein said protection mechanism includes means for de-energizing said energizing circuit and energizing said fuel feed terminating device when said start signal is received by said energizing circuit after the engine has started, to thereby permit an operator to stop the engine from a remote location.
 11. A system as recited in claim 1, wherein said protection mechanism further includes means for sequentially energizing and deenergizing auxiliary equipment a predetermined period of time after said start signal is received by said energizing circuit. 